Process for producing combined coal char and oil coke and coproducts therewith



Aprll 8, 1969 A. D. SINGH 3,437,562

PROCESS FOR PRODUCING COMBINED COAL CHAR ANI) OU, COKE AND COFRODUCTS THERFIWTTH Filed Dec. 1964 3,437,562 PRocnss non PRonUcING CoMBINED COAL CHAR AND ou. conn AND coPRoDUCTS rHnRuwrrH Alamjir n. Singh, 401s N. Whipple si.,

Chicago, Ill. 60618 Filed Dec. 3, 1964, Ser. No. 415,603 Int. Cl. (110i) 55/00 U.S. Cl. 201-22 10 Claims ABSTRACT F THE DISCLOSURE coker are introduced into a heat generator within which further reaction takes place, there being means for effecting an interchange of material between the coal devolatilizer and the heat generator, and between the oil fluid coker and the generator. Means is provided for effecting further byproduct recovery from the heat generator, and for withdrawing from the heat generator a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

This invention relates to the treatment and production of fuels, and concerns more specifically the production of a carbonaceous fuel which is a combination of coal char and oil coke.

Char, as normally produced from oil, is a generally granular carbonaceous material which because of certain of its desirable characteristics has found acceptance in industry, for example as a fuel. However, char made from coal also has certain relatively undesirable characteristics which have retarded or inhibited its acceptance for many industrial uses. For example, char from coal is very reactive as a fuel, and it is lower in sulphur content than the coal from which it is made, but it has an appreciably higher ash content, as compared with the coal from which it is produced, rendering its use less desirable in many instances. In the prior patent to Alamjit D. Singh, No. 2,512,076 dated I une 20, 1950, there is set forth a process for the production of char, with its byproducts from the coking of bituminous coals by the use of a duid-bed technique.

Fuel for industry has also been produced by the coking of heavy oils, which upon coking or thermocracking yield a carbonaceous free flowing residue, frequently referred to as iiuid coke, along with certain amounts of liquid and gaseous byproducts. The fluid coke produced from oil has also found acceptance in industry as a fuel, but like char from coal, is possessed of certain undesirable characteristics which have inhibited or retarded the acceptance of lluid coke for use as a fuel or the like in many industrial applications. For example, when oil is coked, it yields a carbonaceous residue or Huid coke, which although generally granular, is diflicult to pulverize, is not highly reactive as a fuel, and is considerably higher in sulphur content as compared with the oil from which it is made. Fluid coke, as made from oil, is considerably more difficult to pulverize than is char made from coal. By reason of the foregoing characteristics, fluid coke as made from the coking or thermocracking of oil, has not found wide acceptance as an industrial boiler fuel.

In accordance with the present invention, it has been found that by the combination of char made from coal Cal with liuid coke made from oil, in a manner, and in aC- cordance with the process hereinafter to be described, a resulting carbonaceous product is produced retaining many of the essential desirable characteristics of each 0f the components, while at the same time eliminating or minimizing undesirable characteristics of such components when individually produced.

Accordingly, one of the objects of the present invention is to provide, as a new product, a combined coal char and oil liuid coke, as a carbonaceous material, useful as a fuel, and for many industrial applications wherein the use of either component would be unacceptable or less desirable.

A further object of the invention is to provide an mproved process for producing a product of the foregoing character, which process may be economically carried out, and properly controlled, whereby to produce a resulting product having the desired characteristics.

A still further object of the invention is to provide in a process as above defined, means for the recovery of the byproducts produced, individually from the treated coal and from the treated oil, `whereby to effect a proper separation, and facilitate the use of such byproducts, for various industrial applications.

Other features and advantages of the invention will be apparent from the following specification, when taken in connection with the accompanying drawings, wherein there is illustrated diagrammatically, an apparatus and process suitable for use in connection with the present invention.

Referring more specifically to the drawing, there is diaygrammatically illustrated, in the figure thereof an apparatus for producing continuously, a combined coal char and oil fluid coke, in accordance with the present invention. There is provided, diagrammatically shown, a heat generator into which material may be charged `by means of conduits 12 and 14. Conduit 12 is adapted for connection to a source of preheated air, and also receives material from a conduit or pipeline 16, under control of a valve 18, leading from the bottom of a coal devolatilizer, diagrammatically indicated by the reference numeral Conduit 14 is likewise adapted for connection to a source of preheated air, and also receives material from a conduit or pipeline 22, under control of a valve 24, connected to the bottom of an oil Huid coker diagrammatically indicated by the reference numeral 26.

The uid coker is arranged to receive preheated oil from a conduit 28, the inner end of which is provided with a series of spray nozzles or other spray devices and the Huid coker is also arranged to receive material from the upper end of the heat generator through a conduit 32 under control of a valve 34.

The coil devolatilizer 20 receives its supply of raw coal, mixed with steam, fuel gas, or other iuidizing media through a conduit 36, which conduit also receives material from a conduit 38 under control of a Valve 40 leading from the bottom of the heat generator.

As shown in the drawing, the apparatus further comprises a pipeline or conduit 42 through which the final carbonaceous residue product is exhausted from the system; and suitable stripping devices as indicated at 44, 46 and 48, the purpose of which will be presently described.

The upper end of the heat generator is provided with a pipe or exhaust conduit 50 through which byproducts discharged from the heat generator may be withdrawn to a suitable-byproduct recovery system. Similarly the coal devolatilizer is provided with an exhaust conduit 52 and the oil uid Coker is provided with an exhaust conduit 54 through which the byproducts from these units may be individually withdrawn for transmission to a suitable byproduct recovery system.

In operation, as previously set forth, raw coal, and steam, fuel gas, or other fluidizing media in introduced into the coal devolatilizer unit through the conduit 36. The coal is preferably bituminous coal, of a particle size for example eight mesh and smaller down to relatively line particles, and it may be either coking or noncoking in character. The steam, when introduced, acts as an oxidizing agent and aids in reducing agglomeration of the material bed within the coal devolatilizer, as discussed for example in said Singh Patent No. 2,512,076. The fuel gas introduced through the conduit 36 improves the action in the coal devolatilizer, and also influences the byproducts recovered from the devolatilizer through the conduit 52. As will be understood, other fluidizing media may Abe introduced through conduit 36 into the coal devolatilizer, either in substitution for the steam and/or the fuel gas, or in addition thereto.

The oil is introduced into the oil uid coker, as previously described, through the conduit 28. In most instances this oil may advantageously be so-called Bunker-C oil, which is in surplus in most oil refineries, and is thus low in price, it being diliicult to nd sufficient advantageous uses for this product. By way of illustration, but not limitation, the oil may be preheated, for example, to about 400 F.; and it is introduced into the fluid coker under pressure so that the spray devices 30, which may be of any suitable construction, may advantageously spray the introduced oil into the interior of the oil Huid coker unit.

Referring to the heat generator 10, this unit, as previously described, receives its supply of material from the conduits 12 and 14. The preheated air supplied to conduit 12 may for example be preheated to 400 F., and as previously described, the conduit 12 also receives material from the coal devolatilizer through conduit 16 under control of valve 18, which material is mixed with the -preheated air which is under pressure and transmitted thereby into the internal chamber of the heat generator. In a similar manner air preheated for example to 400 F. and under pressure, transmits the material from the oil iiuid Coker from conduit 22 under control of valve 24, through the conduit 14, into the internal combustion chamber of the heat generator.

Within the heat generator a partial combustion of the char received from the coal devolatilizer, and the fluid coke received from the oil fluid coker takes place with the preheated air, raising the temperature of the material bed, in an illustrative example, to 1,200 F. The air underA pressure, received into the heat generator through the conduits 12 and 14, effects an agitation of the material bed within the heat generator, preventing agglomeration, and providing sufficient agitation to facilitate the partial combustion and mixing of the product.

A proportion of the mixed material from the heat generator passes downwardly through conduit 38 under control of valve 40 to be introduced through conduit 36 into the coal devolatilizer, and another proportion of the mixed product from the heat generator is withdrawn through conduit 32 under control of valve 34 for transmission into the oil fluid Coker unit 26. Byproducts from the heat generator, as for example CO and steam, are withdrawn from the unit through the conduit as previously described.

In the oil fluid coker unit 26 the material drawn through conduit 32 mixes with the incoming preheated oil from conduit 28, in the production of fluid coke within the unit 26; and while the material withdrawn therefrom through conduit 22 may therefore be primarily or predominantly fluid coke, it will also contain a degree of char, by reason of the continuous recirculation arrangements provided. In a similar manner while the material withdrawn from the lower end of the coil devolatilizer through the conduit 16 may be predominantly coal char, it also includes fluid coke from the oil, by reason of the continuous circulation system.

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The byproducts from the coil devolatilizer 30 and from the oil iiuid coker 26 are individually withdrawn through the conduits 52 and 54 respectively, for transmission to suitable byproduct recovery systems. The nal carbonaceous residue product is withdrawn from the heat generator through conduit 42 under control of a valve 56.

Steam may -be advantageously used as a stripping medium in the conduits or devices 44, 46 and 4S, such steam being introduced through the conduits shown into the respective units near the bottoms thereof in the vicinity of the outlets, whereupon it sweeps upwardly through the units, aiding in sweeping the byproducts upwardly, for discharge through the conduits 50, 52 and 54, and preventing the byproducts from passing downwardly through the conduits, such as 22, 38 and 16, leading from the bottom of the respective units of the system.

The carbonaceous residue product delivered from the system through the conduit 42 will be a combination of char from the raw coal introduced through conduit 36, and huid coke from the oil, such for example as Bunker-C oil, introduced into the system through the conduit 28. However, such resulting :product will be not just a mechanical mix or proportioning of char and fluid coke, but will on the contrary be a combination product of coal char and oil fluid coke, wherein the individual granules or particles which may for example have a grain size approximating that of the incoming coal, will comprise a combination of the coal char and the oil fiuid coke, in intimate association and in proportion to tli'e raw materials introduced, which may be varied within wide limits. The carbonaceous residue product produced is thus neither coal char nor oil fluid coke, but is rather a combination thereof, combining essential desirable characteristics of the two components, while eliminating or minimizing to a considerable degree undesired characteristics of the component materials.

For example, by causing the fluid coke from the coker 'or oil cracking unit 26 to have a certain time of residence in the coal devolatilizer 20, there results a partial desulphurization of the fluid coke, and a coating thereof with a highly reactive coal char surface, which facilitates the effective ignition of the resulting carbonaceous residue product in boiler furnaces, when used as a fuel.

As previously pointed out, the ash content of char from coal is considerably higher than the ash content of the coal from which it is produced, and it has been found that such high ash content in normal coal char tends to increase slagging in boiler furnaces wherein the coal char may be used as fuel. In accordance with the present invention the carbonaceous residue product produced may upon proper proportion of the components have a significantly lower ash content, below that of the raw coal, avoiding ash content problems in the use of the material as fuel, with resulting increase operating economy and fuel value.

As has been previously pointed out, Bunker-C oil is presently in excess suptply in most refineries because of its limited utility and value. By reason of the present process iiuid coke lproduced therefrom is enriched as to reactivity by the coal char, converting lit into a desirable fuel material.

In the process and alpparatus hereinbefore described it is to be noted that the heat of the partial combustion generated in the heat generator 10 is transmitted with the material through conduit 32 into the iiuid coker unit 26, and through the conduits 38 and 36 into the coal devolatilizer unit 20, wherelby the heat from a common heat generator maintains the operation both of the oil fluid coker and of the coal devolatilizer, thus effecting important economies in operation. For example, the material generated to a temperature of 1,200" F. in the heat generator unit 10 may maintain temperature conditions within the fluid coker and within the coal devolatilizer at approximately 900 F., in an illustrative installation. As will be understood, such temperatures, and the @proportioning of the product in the recirculation system, may be readily controlled by controlling the temperature of the incoming .preheated air, and by controlling the rate and magnitude of recirculation through the several valve controlled conduits. The continuous circulation and proportioning provides for the proper combination in theresulting carbonaceous residue product, whereas the recovery products from the individual units are maintained separated in the conduits 50, 52 and S4 for maximum utilization. These liquid and gaseous recovery products will be akin to those normally recovered from coal devolatilizer and oil fluid coker units and installations.

In standard fluid coking units agglomeration has also been a problem, it frequently being necessary to withdraw a certain quantity of the fluid coke from the unit, grind it, and return it as a feed material so as to avoid such agglomeration and the building urp of unduly large particle size pellets. In accordance with the present process the addition of the coal char minimizes these undesired characteristics in the operation of the fluid coker.

As will be understood, the oil fluid coker unit 26 is in effect an oil cracking unit from which gasoline and gas oil will be normally included in the byproducts recovered through conduit 54. By means of the present process it will be seen that these products will be produced from the Bunker-C oil, thus increasing the gasoline and gas oil production from the original crude.

If desired, a difllcultly combustible fuel, such for example as beneficiated cinder, may be introduced into the coal devolatilizer along with the raw coal through conduit 36, and in accordance with the present process, such diflicultly combustible fuel may be rendered satisfactory and usable as a boiler furnace fuel by causing it to be engulfed by the highly reactive char material resulting from the devolatilization `of the coal.

It is obvious that various changes and modifications may be made without departing from the spirit of the invention. The invention is accordingly not to be limited, except as is indicated by the following claims.

The invention is hereby claimed as follows:

1. The method of producing a granular carbonaceous product which comprises separately subjecting coal to the action of heat to devolatirize the coal and produce a coal char, separately. subjecting oil to the action of heat to crack the oil and produce a fluid coke, and mixing the char and the fluid coke while subjected to the action of heat to provide a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

2. The method of producing a granular carbonaceous product which comprises introducing coal into a first chamber, subjecting the coal therein to the action of heat to devolatilize the coal and produce a coal char, introducing oil into a second chamber, subjecting the oil therein to the action of heat to crack the oil and produce a fluid coke, introducing a mix of the char and the fluid coke into a third chamber, and subjecting the mix to the action of heat therein to provide a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

3. The method of producing a granular carbonaceous product as defined in claim 2 wherein the coal char, oil fluid coke, and carbonaceous product are continuously recirculated between said chambers.

4. The method of producing a granular carbonaceous product as defined in claim 2 wherein byproducts are individually collected from each of said chambers.

5. Apparatus for producing a granular carbonaceous product which comprises a first chamber, means for supplying coal thereto, means for supplying heat thereto to devolatilize the coal and produce a coal char, a second chamber, means for introducing oil into said second chamber, means for supplying heat to the second chamber to crack the oil therein and produce a fluid coke, a

third chamber, means for introducing the char and fluid coke therein, and means for supplying heat to the mix within the third chamber to thereby provide a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

6. Apparatus for producing a granular carbonaceous product as defined in claim 5 wherein conduit means is provided connected to each of said chambers for withdrawing byproducts therefrom.

7. Apparatus for producing a granular carbonaceous product as defined in claim 5 wherein there is conduit means connected to each chamber for withdrawing byproducts therefrom, and stripping mechanism for directing the byproducts to said conduit means.

8. Apparatus for producing a granular carbonaceous product which comprises a first chamber, means for supplying coal thereto, means for supplying heat thereto to devolatilize the coal and produce a coal char, a second chamber, means for introducing oil into said second chamber, means for supplying heat to the second chamber to crack the oil therein land produce a fluid coke, a third chamber, valve control conduits interconnecting the first chamber and the second chamber with the third chamber for introducing the char and fluid coke therein, and means for supplying heat to the mix within the third chamber to thereby provide a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

9. Apparatus for producing a granular carbonaceous product which comprises a first chamber, means for supplying coal thereto, means for supplying heat thereto to devolatilize the coal and produce a coal char, a second chamber, means for introducing oil into said second chamber, means for supplying heat to the second chamber o to crack the oil therein and produce a fluid coke, a third chamber, a valve controlled conduit interconnecting the first chamber and the third chamber for introducing the char to the third chamber, a valve controlled conduit interconnecting the second chamber and the third chamber for introducing fluid coke into the third chamber, an additional valve controlled conduit interconnecting the first chamber and third chamber for transmitting material from the third chamber into the first chamber, and an additional conduit interconnecting the second chamber and the third chamber for transmitting material from the third chamber to the second chamber, and means for supplying heat to the mix within the third chamber to thereby provide a carbonaceous product the individual particles of which comprise combined coal char and fluid coke.

10. The method of producing a granular carbonaceous product which comprises separately subjecting coal and oil in predetermined proportions to the action of heat to devolatilize the coal and crack the oil, and thereafter further processing a mix of the coal and oil to provide a carbonaceous product the individual particles of which comprise combined coal char and oil fluid coke.

References Cited UNITED STATES PATENTS 1,972,944 9/ 1934 Morrell 208-8 1,986,593 1/1935 Morrell 208-8 2,640,016 5/ 1953 Martin 201--22 2,895,904 7/1959 Jones et al. 201-31 FOREIGN PATENTS 586,834 11/1959 Canada.

NORMAN YUDKOFF, Primary Examiner.

D. EDWARDS, Assistant Examiner.

U.S. Cl. X.R.

U.S. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D C. 20231 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,437,562 April 8, 196

Alamjit D. Singh It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column l, line 36, "produced from oil" should read produced from coal Column 2, line 53 and column 3, line 72, "coil", each occurrence, should read Coal Column 3, line 2, "media in" should read media is Column 4 line l, "from the coil devolatilizer 30" should read from the coal devolatilizer 2O Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Edward M. Fletcher, J r.

Commissioner of Patents Attesting Officer 

